While the prorogation of Parliament has generated political controversy, constitutional lawyers are asking whether the government acted legally in advising the Monarch. The legal challenges to the prorogation will face a number of hurdles. Even if the prerogative power is justiciable, there are difficult questions in identifying the specific legal issue. When writing about a potential challenge in June, Lord Pannick stated that one legal objection is that ‘the prime minister would be seeking to prorogue parliament for the purpose of avoiding parliamentary sovereignty on an issue of significant constitutional importance’. This post will explore a related line of argument, which focuses on proroguing Parliament as a means to avoid political accountability (so the argument does not rely on the language of sovereignty). The starting point in the line of argument is that the prorogation will to some degree hinder Parliament in whatever it wants to do in the period immediately prior to Britain exiting the EU. That goes beyond the potential to enact legislation or pass a motion of no confidence, and also includes the ordinary channels of political accountability and scrutiny of government.

Against this starting point, it can be countered that the government is not under a legal duty to maximise political scrutiny of its actions or make political opposition easier. However, the challenge to the advice to prorogue does not rest on such a vague or open-ended duty. Instead, the argument is that the government has acted contrary to existing expectations and past practice and done so at a time of political sensitivity. Parliament still has some days to act (so the government supporters say accountability is not foreclosed), but the measure means Parliament has less time than would normally be the case. While the government can still be held to account retrospectively in future months (so some accountability will be possible), by then it may be too late to reverse the government’s decisions (if there is an exit from the EU with no deal). The decision to act contrary to prior expectations and practice therefore warrants a high burden of justification from the government.

So far, an objection to the prorogation has been stated, but does this become a legal objection? Lord Sumption has argued not, stating that the objection is that the government’s action was ‘taken for questionable political motives’ and that is not sufficient to render the decision unlawful. According to that view, the remedy lies in the political sphere, not in the courts. However, Lord Sumption’s reference to ‘political motives’ does suggest a possible challenge on the basis that the government acted for political purposes. The political purposes doctrine has long been a ground for the judicial review of executive action. Over a century ago, Farewell LJ stated that political considerations are ‘pre-eminently extraneous’ (R v Board of Education (1910)). Exercising a statutory discretion simply to avoid political embarrassment will therefore fall foul of this principle (Padfield v Ministry of Agriculture, Fisheries and Food (1968)). Similarly, a decision not to stock certain newspapers in a public library simply because a local authority disagrees with the paper’s editorial stance would be unlawful (see R v London Borough of Ealing and Others, ex p Times Newspapers Ltd (1987)). If it can be established that the government is proroguing Parliament for political purposes, is the decision vulnerable to legal challenge on that basis?

The phrase ‘political purposes’ can be unhelpful. For a system of democratic accountability to work, politicians are expected to act for political purposes – most obviously in seeking to win votes by devising policies that will attract public approval. As Lord Bingham stated in Porter v Magill:

‘Elected politicians of course wish to act in a manner which will commend them and their party (when, as is now usual, they belong to one) to the electorate. Such an ambition is the life blood of democracy and a potent spur to responsible decision-taking and administration. Councillors do not act improperly or unlawfully if, exercising public powers for a public purpose for which such powers were conferred, they hope that such exercise will earn the gratitude and support of the electorate and thus strengthen their electoral position. The law would indeed part company with the realities of party politics if it were to hold otherwise.’

What makes a political purpose unlawful? Lord Bingham went on to elaborate:

‘a public power is not exercised lawfully if it is exercised not for a public purpose for which the power was conferred but in order to promote the electoral advantage of a political party.’

An obvious example would be a decision to give significant public funds to the governing political party (and no other party) for the simple purpose of conferring an advantage in a coming election. The doctrine applies more easily to statutory powers, which may be conferred for a specific purpose (or have such a purpose inferred). However, there is no reason why the doctrine could not apply to a clear politically motivated misuse of a prerogative power.

Sometimes the court explains the legal objection as applying to ‘purely political’ purposes. Such a phrase indicates that the measure in question is devoid of any merit aside from the political considerations and is thereby an abuse of power. As Lord Scott explained in Porter v Magill:

‘there is all the difference in the world between a policy adopted for naked political advantage but spuriously justified by reference to a purpose which, had it been the true purpose, would have been legitimate, and a policy adopted for a legitimate purpose and seen to carry with it significant political advantage.’

That, in turn, gets the court into difficult questions of whether the decision is ‘purely political’ or whether other grounds can support it. That is a key issue in the current controversy, as the government claims that the prorogation is not related to Brexit and nothing out of the ordinary.

It is possible to take the legal argument further, so that the question is not simply whether the decision is ‘purely political’ or not. Instead, the issue is also about how the political advantage is secured. A political purpose may be legitimate where it is implementing a policy in the belief that the public or MPs will approve of it. As stated, the system of representative democracy is based on such incentives. Accordingly, while a promise or decision to implement popular measures immediately prior to an election may be rhetorically characterised as a ‘bribe’, it is not automatically unlawful simply as it is calculated to secure political support. The legal objection arises where the advantage is secured by short circuiting the very process of political accountability that legitimates the exercise of public power. Along such lines, gerrymandering (and the analogous issue in Porter v Magill) is problematic because it taints the electoral process, through which such policies are to be publicly evaluated. Such a measure is not political in the sense of generating political approval, but instead seeks to undermine the channels through which political disapproval can be expressed. Under this line of argument, the key distinction is between the government playing its hand of cards well to secure a desired outcome, and the government attempting to stack the deck in its favour.

The line of argument could apply not just under the purposes doctrine and could be relied on in a rationality challenge (which may arise where it cannot be shown that the decision was primarily/purely political) to require a particularly strong justification from the public body. While many of the leading cases discuss the issue in relation to electoral advantage, there is no reason to limit the objection to party politics and elections. A decision taken simply to avoid political embarrassment may be unlawful, even when outside the context of an election. Similarly, the example of newspapers in a public library given earlier is not about an electoral advantage. More broadly, the decision in Evans v Attorney General can be understood as requiring a high level of justification before ministers can prevent the release of information that would otherwise be made available under a statute designed to promote political accountability.

An election is one component of a representative democracy, but there are other processes that are also crucially important. Government is expected to be accountable to Parliament. In this context, it is legally objectionable for government to use its powers to avoid or subvert the ordinary processes of scrutiny, checks and accountability because such processes happen to be politically inconvenient. The line of argument points to a key objection to the prorogation, that it is a political measure designed to curb the opportunities for accountability during a sensitive period in which an irreversible decision of political and constitutional importance may be made. For that reason, the argument runs that the matter cannot simply be left to the ordinary political channels to express opposition to the measure, as those ordinary channels are being closed down for a temporary (yet crucial) period.

Whatever is decided on the prorogation, it may not be decisive in relation to Brexit. Even if Parliament has extra days to scrutinise government, it is not clear what exactly it would do and whether opponents to the government’s policy would be out-manoeuvred. However, the legal challenge will raise an important set of constitutional issues, with possible implications for the way a government can manage the channels of political accountability.

With thanks to Jeff King and Mark Elliott for comments on an earlier draft.

Jacob Rowbottom is a Professor of Law at the University of Oxford and author of Media Law.